辽河口湿地不同类型湿地土壤酶活性分析

Analysis on Soil Enzyme Activities of Different Types Wetland Soil in Liaohe Estuary

土壤酶活性对于河口湿地土壤物质循环具有重要意义,研究辽河口湿地土壤理化性质和酶活性,探讨土壤酶活性与理化性质间的相关性,考察盐处理对土壤酶活性的影响,以期明确不同类型湿地土壤酶活性的影响因素。以辽河口芦苇、翅碱蓬和裸滩湿地为研究对象,测定不同土层深度(0~10,10~20,20~30,30~40cm)土壤理化性质(pH、电导率、有机质含量和全氮含量)和土壤脲酶、磷酸酶、蔗糖酶和脱氢酶活性。研究结果表明:芦苇湿地的土壤pH值较低,裸滩湿地的土壤pH值较高;翅碱蓬湿地和裸滩湿地的土壤电导率高于芦苇湿地,随土层深度的增加土壤电导率均呈降低趋势;芦苇湿地0~10cm土层土壤有机质含量较高,但30~40cm土层土壤较低,随着土层深度的增加,3种类型湿地土壤有机质含量均呈降低趋势。随土层深度的增加土壤全氮含量呈降低趋势,0~10cm土壤芦苇湿地全氮含量最高,30~40cm土层不同湿地类型土壤全氮含量趋同。随着土层深度的增加,4种土壤酶活性均呈现出降低的趋势,且不同湿地类型间0~10cm土层土壤酶活性差异较30~40cm土层大,其中芦苇湿地0~10cm土层的土壤脲酶活性、磷酸酶、蔗糖酶和脱氢酶活性均最高。芦苇湿地土壤脲酶、磷酸酶、蔗糖酶和脱氢酶活性与土壤pH值呈极显著负相关(p<0.01),与有机质和全氮含量呈显著正相关(p<0.05);翅碱蓬湿地仅土壤脲酶活性和全氮含量呈现显著相关(p<0.05);裸滩湿地仅土壤脲酶活性与全氮含量呈极显著正相关(p<0.01)。盐处理使不同湿地类型土壤脲酶和磷酸酶活性明显降低。

Soil enzyme activities in wetland of estuary play an important role in material cycle. We investigated soil physical and chemical properties and enzyme activities of coastal wetlands, analyzed the relationship between soil enzyme activities and physical and chemical properties, and studied effects of different salt contents on soil enzymes, aiming to explore the influence factors on soil enzyme. Wetlands of reed, suaeda and nude beach were taken as objects, soil physical and chemical properties(pH, conductivity,organic matter content and total nitrogen content) and enzyme(urease, phosphatase, sucrase and dehydrogenase) activities were detected in different soil layer depths of 0-10 cm, 10-20 cm, 20-30 cm and 30-40 cm. The results showed that the pH value of reed wetland was lower while the pH value of nude beach wetland was higher. Soil conductivities of suaeda and nude beach wetlands were higher than that of reed wetland. The soil conductivities decreased with the increase of soil depth. Contents of soil organic matter in 0-10 cm layer was higher in reed wetland, but lower in 30-40 cm layer. The contents of soil organic matter decreased with the increase of soil depth in three types of wetlands. Total nitrogen content in 0-10 cm layer of reed wetland was the highest, and total nitrogen contents were almost the same in 30-40cm layer of three wetland types. The contents of total nitrogen contents decreased with the increase of soil depth. The four soil enzyme activities decreased with the increase of soil depth in 3 types of wetlands. The differences of soil enzyme activities in 0-10 cm layer were bigger than that in 30-40cm. Enzyme activities of urease, phosphatase, sucrase and dehydrogenase were the highest in 0-10cm layer of reed wetland. Activities of urease, phosphatase, sucrase and dehydrogenase in reed wetland were negatively correlated with soil pH values extremely(p<0.01) and positively correlated with contents of organic matter and nitrogen(p<0.05). Urease activity of suaeda was positively correlated with contents of total nitrogen(p<0.05). Urease activity of nude beach wetland was positively correlated with contents of total nitrogen extremely(p<0.01). Activities of urease and phosphatase in 3wetlands decreased significantly under salt treatments.